Aerial ladder.



'No. 69!,879. Patented Ian. 28, I902. F. S. SEAGBAVE.

AERIAL LADDER.

(Application filed June '7, 1901..)

(No Model.)

w m w ATTORNEY m: uon'ms PETERS co., PHCIIWILII'HD,WASMINGTON, a. c,

llNiT rates FREDERIO S. SEAGRAVE, OF COLUMBUS, OHIO.

AERIAL LADDER.

SPECIFICATION forming part of Letters Patent No. 691,879, dated January 28, 1902.

Application filed .Tu e 7, 1901.

To aZZ whom it may concern;

Be it known that I, FREDERIO S. SEAGRAVE,. a citizen of the United States, residing at O- lumbus, in the county of Franklin and State of Ohio, have invented a certain new and useful Improvement in Aerial Ladders, of which the following is a specification.

My invention relates to the improvement of aerial ladders, and has particular relation to mechanism for raising the same from a supporting-truck or turn-table.

The objects of my invention are to provide a combined screw and spring actuated ladder-raising mechanism of superior "construction and arrangement of parts, to so construct my improved lifting mechanism as to permit of the same being arranged in a compact form and connect with the ladder in a simple manner, and to produce otherimprovements the details of which will be more fully pointed out hereinafter. These objects I accomplish in the manner illustrated in the accompanying drawings, in which Figure 1 is a side elevation of the rear or lower portion of a ladder, showing my improved elevating mechanism in connection therewith. Fig. 2 is a transverse section on line 00 as of Fig. 1. Fig. 3 is a sectional view on line y y of Fig. 1, and Fig. at is a central longitudinal section through the combined screw and spring casing.

Similar numerals refer to similar parts throughout the several views.

1 represents the side frame-bars of the ladder, which are connected at intervals by rungs 2. As shown in the drawings, the ladder is provided with a hinged or swinging support through the medium of brace and supporting arms 3, 4, and 5, the upper ends of which are connected with the outer sides of the ladder-bars. These converging brace-bars at each side are united at their lower ends and journaled or hinged on a transverse shaft 6, mounted in suitable hearings on a truck turn-table, a portion of which is indicated at 7. When the ladder is in its'lowered position, the supporting-arms 5 are substantially vertical, while the brace and supporting arms at and 5 incline forwardly from their point of junction. Pivotally supported in the lower ends of depending ladder-brackets 8, which are arranged on opposite sides $eria1No. 63,505- (No model.)

of the ladder, are the outwardly-extending trunnions 9 of a bearing-ring 10, which is preferably centrally beneath the ladder, and within and rigidly connected with this ring 10 is a cylindrical casing 11, which extends beneath the ladder and in the direction of the length thereof. This casing has its outer end portion 11 provided with an inwardlyextending central and internally-threaded sleeve 12, which may terminate at a desired point within the casing 11. Extending movably through a central opening in the rear end of the casing 11 and terminating normally at a point near the inner end of said casing is a tube 13, the latter loosely surrounding the internal sleeve 12. Thistube 13, which extends rearwardly from the casing 11, has connected therewith in its rear portion a bearing-ring 14, the oppositelylocated trunnions 14 of which are journaled in the vertical and parallel arms of a bearing bracket or standard 15, which rises from the turn table 7. Passing loosely through the tube 3 and passing through and engaging the threads of the internal casingsleeve 12 is an operating screw-rod 16, which screw may, as indicated in Fig. 4 of the drawings, extend through the forward end opening of the casing 11. Both within and without the rear end of the tube 13 the screw-rod is provided with stop-shoulders, which are indicated at 18 and 19, and on its rear or outer termination said screw-rod carries a hand or balance wheel 20. Within the casing 11 and surrounding the tube 13 is a coiled spring 21, the forward end of the latter bearing against an end flange 13 of said tube, while the rear end of the spring bears against the end of the casing 11.

In utilizing my invention it will be understood that the turning of the hand or balance wheel 20 to the right will result in the casing 11, together with the ladder, being swung in the arc of a circle rearwardlyand downwardly and in, the raising of the forward portion of the ladder until the latter is in the position indicated in dotted lines. It will also be seen that the elevating screw-power thus imparted will be greatly assisted by the pressure of the spring 21 against the rear or inner end of the casing 11, said spring being normally or when the ladder is in its lowered position under compression. It will be observed that the spring and screw in the construction shown and described are arranged in compact form and adapted to operate in conjunction with each other, so as to permit the ladder being rapidly raised with comparative ease.

Although the part 11 is herein described and shown as a cylindrical casing, it is obvious that the same might be in the nature of an elongated frame of suitable construction.

It will be understood that the raising mechanism herein described,consistin g of the screw and spring, may be adapted for the purpose of raising water-towers or other bodies adapted to swing or be elevated from a hinged or pivoted base portion. 7

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In an aerial ladder, the combination with a ladderhavingits rear portion fulcrumed and a casing or frame 11 having an internallythreaded nut or sleeve, of a screw entering said casing and engaging the threads of said sleeve, a spring within the casing and loosely surrounding said screw, said spring adapted to exert a raising pressure on the ladder, substantially as specified.

2. In an aerial ladder, the combination with a ladder fulcrumed at its rear end, of a frame or casing 11 pivotally connected therewith, a threaded sleeve or nut in said casing, a tubular body 13 extending Within said casing and surrounding said sleeve, a spring interposed between the flanged outer end of said tube and the inner end of the casing, said tube having a pivotal support in its rear portion and a screw extending through said tube and engaging the threads of said sleeve or nut, substantially as specified.

FREDERIG S. SEAGRAVE. In presence of-.

O. O. SHEPHERD, V. L. MoRRoW. 

